Methods for lead penetrating clamping system

ABSTRACT

An apparatus and method of forming improved wire bonds between the contact pads on semiconductor devices and individual lead frame fingers of a lead frame. The apparatus and method include the use of a penetrating individual independent lead finger clamp during the wire bonding process to provide increased stability of the individual lead finger for improved bonding by the clamp penetrating a portion of the lead finger being bonded. If desired, the apparatus and method also provide for the use of either a penetrating or non-penetrating fixed clamp for the lead fingers during the wire bonding process in addition to the penetrating individual independent lead finger clamp during the wire bonding process to provide increased stability of the individual lead finger for improved bonding.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/091,688,filed Mar. 5, 2002, now U.S. Pat. No. 6,604,670, issued Aug. 12, 2003,which is a continuation of application Ser. No. 09/797,380, filed Mar.1, 2001, now U.S. Pat. No. 6,419,145, issued Jul. 16, 2002, which is acontinuation of application Ser. No. 09/421,170, filed Oct. 19, 1999,now U.S. Pat. No. 6,206,274, issued Mar. 27, 2001, which is acontinuation of application Ser. No. 08/909,230, filed Aug. 11, 1997,now U.S. Pat. No. 6,047,877, issued Apr. 11, 2000, which is acontinuation of application Ser. No. 08/631,143, filed Jun. 17, 1996,now U.S. Pat. No. 5,673,845, issued Oct. 7, 1997.

This application is related to application Ser. No. 08/597,616, filedFeb. 6, 1996, now U.S. Pat. No. 5,647,528, issued Jul. 15, 1997,entitled “BONDHEAD LEAD CLAMP APPARATUS AND METHOD” and assigned toMicron Technology, Inc. and is also related to Ser. No. 08/592,058,filed Jan. 26, 1996, now U.S. Pat. No. 5,954,842, issued Sep. 21, 1999,entitled “LEADFINGER CLAMP ASSEMBLY” and assigned to Micron Technology,Inc.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is related to forming wire bonds between thecontact pads on semiconductor devices and individual lead frame fingersof a lead frame.

More specifically, the present invention is related to the apparatus andmethod of forming improved wire bonds between the contact pads onsemiconductor devices and individual lead fingers of a lead frame usingone or more independently actuated lead penetrating bond head leadclamps or a fixed bond head clamp which may be either penetrating or notduring the wire bonding process.

2. State of the Art

Well known types of semiconductor chip devices are connected to acomponent known as lead frames and subsequently encapsulated in plasticfor use in a wide variety of applications. The lead frame is typicallyformed from a single continuous sheet of metal, typically by metalstamping operations. The lead frame includes an outer supporting frame,and may include a central semiconductor chip supporting pad and aplurality of lead fingers, each lead finger having, in turn, a terminalbonding portion near the central chip supporting pad. Ultimately, theouter supporting frame of the lead frame is removed after the wire bondsbetween the contact pads of the semiconductor chip device and the leadfingers have been made and after the encapsulation of the semiconductorchip and portion of the lead fingers.

Since the lead frames are formed continuously using stamping operations,they are typically continuously rolled on a suitable reel and providedfor use. Such reeling operations of the lead frames cause the leadframes to have induced stresses and deformations therein leading to leadframes exhibiting longitudinal curvature and transverse curvature, aswell as deformation of the individual leads of the lead frame. Such leadframe curvature and any attendant deformation of the leads and leadframe cause problems in the formation of reliable wire bonds with thecontact pads of semiconductor devices and the individual lead fingers ofthe lead frame. Particularly, problems arise when the size of thesemiconductor is decreased, the number of contact pads on thesemiconductor device is increased, and the number of lead fingers on thelead frame is increased. In order to form the desired connectionsbetween the bond pads of a semiconductor device and a lead frame duringthe wire bonding process, the lead fingers of the lead frame must beimmobilized in a known, predetermined location with respect to thesemiconductor device.

Typical apparatus and methods for forming the wire bonds between thecontact pads on semiconductor devices and the lead fingers of leadframes are illustrated in U.S. Pat. Nos. 4,361,261, 4,527,730,4,600,138, 4,653,681, 4,765,531, and 5,465,899. However, such apparatusand methods do not address the problem of deformed lead frames and theireffect on the wire bonds.

Typically, the deformation of the lead frames and its effect on thequality of wire bonds have been dealt with through the use of clamps onportions of the lead frames during the wire bonding operation. In U.S.Pat. No. 4,434,347 a circular fixed clamp is used to retain the leadfingers of the lead frame during the wire bonding operation. A springloaded electrode is used to heat the end of the lead finger to helpimprove bonding of the wire.

In U.S. Pat. No. 5,322,207 a fixed clamp is used to retain the leadframe during the automated wire bonding process for connecting the bondpads of a semiconductor device to lead fingers of a lead frame.

In U.S. Pat. No. 5,307,978 a fixed clamp is illustrated for use in anapparatus and method for orienting bonding sites of a lead frame at abonding station of an automatic wire bonder.

In U.S. Pat. No. 5,035,034 a hold-down clamp having a multi-fingeredinterchangeable insert for wire bonding semiconductor lead frames isillustrated. The circular clamp insert includes a plurality ofindividual fingers used to bias a lead finger of a lead frame in thewire bonding process to provide a better wire bond by attempting toimmobilize the lead frame during bonding operations.

In U.S. Pat. No. 3,685,137 the jaws of a lead frame clamp are used toforce the lead fingers of a lead frame into a fixed position during thewire bonding process.

In U.S. Pat. No. 4,821,945 a method and apparatus for the single leadautomated clamping and bonding of lead fingers of lead frames areillustrated. However, such apparatus and method are used to replace thefixed clamp during such wire bonding. Additionally, the individual clampis concentrically located with respect to the wire bonding apparatus andmust rotate therearound during wire bonding operations.

While such prior art apparatus and methods have been directed inattempting to solve the problems of forming reliable wire bonds betweenthe contact pads of semiconductor devices and lead fingers of leadframes, they have not been as successful because none of the prior artclamps effectively immobilizes a lead finger during wire bondingoperations as the clamps merely engage the surface of a lead finger, ifproperly positioned thereon.

The present invention is directed to an improved wire bonding apparatusand method for forming wire bonds between semiconductor devices and leadframes by immobilizing the lead finger during the wire bonding process.

BRIEF SUMMARY OF THE INVENTION

The present invention is related to the apparatus and method of formingimproved wire bonds between the contact pads on semiconductor devicesand individual lead frame fingers of a lead frame. In one instance, thepresent invention includes the use of a penetrating individualindependent lead finger clamp during the wire bonding process to provideincreased stability of the individual lead finger for improved bondingby the clamp penetrating a portion of the lead finger being bonded. Inanother instance, the present invention also provides for the use ofeither a penetrating or non-penetrating fixed clamp for the lead fingersduring the wire bonding process in addition to the penetratingindividual independent lead finger clamp during the wire bonding processto provide increased stability of the individual lead finger forimproved bonding. The present invention also contemplates thereplacement of the penetrating fixed clamp with another, or second,penetrating independent clamp in addition to the first individualindependent lead finger clamp during the wire bonding process. With theimproved clamping of the lead finger by the clamp penetrating a portionof the lead finger the present invention allows improved wire bondimpressions and improved bond strength.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention will be better understood when the description ofthe invention is taken in conjunction with the drawings wherein:

FIG. 1 is a perspective view of an independent individual clamp and afixed clamp used in a wire bonding process;

FIG. 1A is a perspective view of a penetrating independent individualclamp and a fixed clamp of the present invention;

FIG. 2 is a perspective view of a lead-over-chip semiconductor devicehaving the bond pads thereof connected to the lead fingers of a leadframe using penetrating independent individual clamps of the presentinvention;

FIG. 3 is a side view of the individual independent clamps used in thewire bonding of a semiconductor chip arrangement;

FIG. 3A is a side view of penetrating individual independent clamps ofthe present invention used in the wire bonding of a semiconductor chiparrangement;

FIG. 4 is a perspective view of a second alternative type of individualindependent lead clamps used in the wire bonding of a lead of a leadframe of the present invention;

FIG. 4A is a cross-sectional view of a penetrating individualindependent clamps of the type illustrated in drawing FIG. 4 of thepresent invention;

FIG. 4B are cross-sectional views of penetrating individual independentclamps of the type illustrated in drawing FIG. 4 of the presentinvention;

FIG. 5 is a perspective view of a third alternative type of independentindividual lead clamp used in the wire bonding of a lead of a lead frameof the present invention;

FIG. 5A is a front view of the penetrating independent individual leadclamp shown in FIG. 5 of the present invention;

FIG. 5B is a side view of the penetrating independent individual leadclamp shown in FIG. 5 of the present invention;

FIG. 5C is a front view of another type of penetrating independentindividual lead clamp shown in FIG. 5 of the present invention;

FIG. 5D is a side view of the penetrating independent individual leadclamp shown in FIG. 5 of the present invention;

FIG. 6 is a perspective view of the use of two independent individuallead clamps used in the wire bonding of a lead of a lead frame of thepresent invention;

FIG. 6A is a cross-sectional view of penetrating independent individuallead clamps of the present invention as shown in FIG. 6 of the presentinvention;

FIG. 6B is a front view of one of the penetrating independent individuallead clamps as shown in FIG. 6A of the present invention;

FIG. 6C is a front view of the other penetrating independent individuallead clamps as shown in FIG. 6A of the present invention;

FIG. 7 is a perspective view of another penetrating independentindividual lead clamp used in the wire bonding of a lead of a lead frameof the present invention;

FIG. 7A is a side view of the penetrating independent individual leadclamp of FIG. 7 of the present invention; and

FIG. 8 is a side view of the penetrating independent individual leadclamp of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to drawing FIG. 1, a semiconductor device (chip or die) 10 isshown being supported by the paddle 12 of a lead frame. A heat block 20is used to heat the paddle 12, die 10, and lead fingers 14 during thewire bonding process. As shown, a suitable wire 16 has one end 17thereof bonded to a bond pad of the die 10. The wire 16 may be of anysuitable type for connection and bonding purposes, such as gold, goldalloy, aluminum, aluminum alloy, etc. The other end 18 of the wire 16 isshown being bonded to the end 15 of a lead finger 14 of the lead frameby a suitable bonding apparatus 26. The bonding apparatus 26 may be ofany suitable type well known in the bonding area, such as a taillessthermosonic or ultrasonic capillary type bonding apparatus whichdispenses wire during the bonding process. As previously stated, thelead finger 14 is in contact with the heat block 20 to heat the leadfinger 14 to a suitable temperature for the bonding operation to helpensure a satisfactory wire bond. If desired, in the wire bondingoperation, further shown in contact with lead finger 14 is a portion ofa conventional clamp 22 used to clamp portions of the lead frame duringsuch bonding operations. The clamp 22 may be of any well known suitabletype, such as those described hereinbefore, and is generic in shape.During the wire bonding process it is desirable for the heat block to beheated to substantially 230 degrees Centigrade. Although the heat blockmay be any suitable temperature during the bonding operation, the heatblock 20 temperature should not exceed 300 degrees Centigrade to preventthermal damage to the die 10. It is further preferred that the bond ofthe other end 18 of the wire 16 made to the end 15 of the lead finger 14be made at a temperature of substantially 190 degrees Centigrade forbonding effectiveness. It is also preferred that the bonding apparatustypically exert a bonding force of substantially 50 to 100 grams whenbonding the other end 18 of the wire 16 to the end 15 of lead finger 14for effective bond formation of the wire 16 to lead finger 14.

The independent clamp 24 (FIG. 1A) may be of any suitable shape for usein independently clamping the lead finger 14, in place of the use ofconventional fixed clamp 22, such as square, semicircular, rectangular,arcuate, etc. Also, as shown, the independent clamp 24 may beresiliently mounted through the use of a shoulder 49 thereon abutting aspring 52 to control the amount of the force exerted on any lead finger14 during the wire bonding operation. If desired, the independent clamp24 may include insulation or cushioning on the end thereof. Theindependent clamp 24 is actuated independently of bonding apparatus 26and has the capability of independent movement along the x-axis, y-axisand z-axis with respect to the bonding apparatus 26. The independentclamp 24 is also free to move about the bonding apparatus 26 and thecentral axis of the die 10 so that any lead finger 14 that is to beconnected to a bond pad on the die 10, regardless of location, may beaccommodated. The independent clamp 24 does not need to be, andpreferably is not, concentrically centered about the bonding apparatus26 so that it will not interfere with the operation thereof. Any desirednumber of independent clamps 24 may be used about the bonding apparatusto minimize the amount of movement of the lead finger 14 between wirebonding operations. The independent clamps 24 may be located inquadrants about the die 10, or in any manner as desired.

Referring to drawing FIG. 1A, a semiconductor device (chip or die) 10 isshown being supported by the paddle 12 of a lead frame in the manner asdescribed in drawing FIG. 1 hereinbefore. Further shown in drawing FIG.1A is an independently actuated lead clamp of the present inventionhaving a lead finger penetrating portion 25 on the bottom thereof usedin place of or in addition to the conventional (fixed) clamp 22 tomaintain the lead finger 14 in position during the bonding process. Theindependent clamp 24 helps ensure that the lead finger 14 is in contactwith the heat block 20 during the bonding process, immobilizes the leadfinger 14 during the wire bonding process, and helps minimize anydeflection of the end 15 of the lead finger 14 so that the bondingapparatus 26 accurately, precisely contacts the end 15 to provide thedesired wire bond. The action of independent clamp 24, and, if desiredthe additional use of fixed clamp 22, provides improved clamping andimmobilization of a lead finger 14 during the wire bonding process, aswell as ensures that the lead finger 14 is in intimate contact with theheat block 20 for effectiveness.

During the wire bonding process it is desirable for the heat block to beheated as described hereinbefore. Similarly, the bonding apparatusshould exert substantially the same amount of force as describedhereinbefore.

The independent clamp 24 (FIG. 1A) may be of any suitable overallexterior shape for use in independently clamping the lead finger 14, inplace of the use of conventional fixed clamp 22, such as square,semicircular, rectangular, arcuate, etc. Also, as shown, the independentclamp 24 may be resiliently mounted through the use of a shoulder 49thereon abutting a spring 52 to control the amount of the force exertedon any lead finger 14 during the wire bonding operation. The independentclamp 24 is actuated independently of bonding apparatus 26 and has thecapability of independent movement along the x-axis, y-axis and z-axiswith respect to the bonding apparatus 26. The independent clamp 24 isalso free to move about the bonding apparatus 26 and the central axis ofthe die 10 so that any lead finger 14 that is to be connected to a bondpad on the die 10, regardless of location, may be accommodated. Theindependent clamp 24 does not need to be, and preferably is not,concentrically centered about the bonding apparatus 26 so that it willnot interfere with the operation thereof. Any desired number ofindependent clamps 24 may be used about the bonding apparatus tominimize the amount of movement of the lead finger 14 between wirebonding operations. The independent clamps 24 may be located inquadrants about the die 10, or in any manner as desired.

Referring to drawing FIG. 2, a lead-over-chip configuration using thepresent invention is shown. The lead fingers 14 are located over thechip or die 10 for wire bonding thereto. In such a configuration, thelead fingers 14 are secured to the die 10 by insulating adhesive strips30. During the bond operation, one or more of the independent clamps 24having a lead finger penetrating portion 25 located on the end thereofclamps the end 15 of lead finger 14 prior to the bonding of a wire 16thereto by one or more of the bonding apparatus 26. The independentclamp 24 applies sufficient pressure to the end 15 of the lead finger 14to compress the insulating adhesive strips 30 to ensure a satisfactorybond between the end of any wire 16 and the end 15 of the lead finger14.

Referring to drawing FIG. 3, a chip or die 10 is shown having aplurality of wires 16 bonded thereto. As shown, one or more of the fixedclamps 22 contacts the end 15 of lead finger 14 aft of the area of thebond of the other end 18 of wire 16 to the lead finger 14. The bonds ofthe other end 18 of wire 16 to the end 15 of the lead finger 14 aretypically a wedge type wire bond, although a ball bond may be made ifdesired. As shown, the heat block 20 is in contact with the paddle 12 ofthe lead frame and the lead fingers 14.

Referring to drawing FIG. 3A, a chip or die 10 is shown having aplurality of wires 16 bonded thereto using the present invention. Asshown, one or more of the independent clamps 24 having lead fingerpenetrating portions 25 located thereon contacts and penetrates the end15 of lead finger 14 aft of the area of the bond of the other end 18 ofwire 16 to the lead finger 14. As also shown, the fixed clamps 22 areformed to have lead finger penetrating portions 22′ thereon whichpenetrate the end 15 of lead finger 14. In this manner, the end 15 ofthe lead finger 14 provides improved clamping and immobilization of alead finger 14 during the wire bonding process as well as ensures thatthe lead finger 14 is in intimate contact with the heat block 20 foreffectiveness. The bonds of the other end 18 of wire 16 to the end 15 ofthe lead finger 14 are typically a wedge type wire bond, although a ballbond may be made if desired. As shown, the clamps 22 and 24 having leadfinger penetrating portions 22′ and 25 thereon, cause the lead finger 14to engage heat block 20, as well as cause heat block 20 to be in contactwith the paddle 12 of the lead frame. However, care should be taken toprevent the lead finger penetrating portion 25 of the independent clamp24 from either damaging the lead finger 14, affecting its electricalcharacteristics, or severing the lead finger 14.

Referring to drawing FIG. 4, a portion of a lead finger 14 is shown inconjunction with a bonding apparatus 26 and modified independentpenetrating lead clamp 22″. The independent lead clamp 22″ is formedhaving a modified end or foot 23 thereon to provide a larger clampingarea of the independent clamp 22″ on the end 15 of the lead finger 14during bonding operations. The modified end or foot 23 is substantiallythe same width as the lead finger 14 and may be mounted to havearticulated movement about the end of the independent clamp 22″, such asusing a pin extending through suitable apertures 28 in a pair of ears 27attached to the foot 23 and the end of the modified independent clamp22″ for illustration purposes. Located on the bottom of the modified endor foot 23 of the independent clamp 22″ are suitable lead finger 14penetrating members (not shown) which penetrate the lead finger 14 toimmobilize it during wire bonding operations as described hereinbefore.

Referring to drawing FIG. 4A, the lead finger penetrating portion 23″ ofthe foot 23 is shown in relation to the bonding apparatus 26 and leadfinger 14. The lead finger penetrating portion 23″ partially penetratesthe lead finger 14 to immobilize the end 15 thereof during wire bondingoperations by the bonding apparatus 26. The lead finger penetratingportion 23″ may penetrate the lead finger 14 to any desired depthdepending upon the thickness thereof. However, care should be taken toprevent the lead finger penetrating portion 23″ from either damaging thelead finger 14, affecting its electrical characteristics, or severingthe lead finger 14.

Referring to drawing FIG. 4B, various embodiments of the lead fingerpenetrating portion 23″ of foot 23 are shown. As shown the lead fingerpenetrating portion 23″ may comprise a plurality of round shaped memberslocated to either extend along the axis of a lead finger 14 or extendtransversely thereof or may comprise a knife edge shape extendingtransversely across the axis of a lead finger 14. The shapes are to bemerely illustrative of a variety of shapes for the lead fingerpenetrating portion 23″ which may be used.

Referring to drawing FIG. 5, an independent clamp 22″ is shown having amodified end or foot 23′ located on the end thereof. The end or foot 23′may be integrally attached to the independent clamp 22″ or may have anarticulated mounting arrangement, such as shown in drawing FIG. 4. Inthis instance, the modified end or foot 23′ is generally semicircular,or arcuate, in configuration so as to engage a large portion of the end15 of the lead finger 14 surrounding the bonding apparatus 26 during thewire bonding operation to hold the end 15 in position.

Referring to drawing FIGS. 5A through 5D, the foot 23′ is shown havingvarious lead finger penetrating portions 23′″ thereon. As illustrated,the various lead finger penetrating portions 23′″ include either a knifeedge shape, as illustrated in drawing FIGS. 5A and 5B, or a blunted edge(rounded edge) shape, as illustrated in drawing FIGS. 5C and 5D. Suchshapes of the lead finger penetrating portion 23′″ are to be consideredmerely as illustrations as other shapes for the penetrating portions maybe used. As previously described, the lead finger penetrating portion23′″ may penetrate the lead finger 14 to any desired depth dependingupon the thickness thereof. However, care should be taken to prevent thelead finger penetrating portion 23′″ from either damaging the leadfinger 14, affecting its electrical characteristics, or severing thelead finger 14.

Referring to drawing FIG. 6, the independent clamp 24 is shown inrelation to the bonding apparatus 26 on the end 15 of a lead finger 14as well as further being shown in relation to a second independentlyactuated clamp 150 located thereon. During wire bonding operations, bothclamps 24 and 150 have portions on the bottom thereof (not shown) forpenetrating the lead finger 14 to immobilize the same during wirebonding operations. The second independently actuated clamp 150 may beof any suitable type and structure such as described and illustratedhereinbefore. The independent clamp 24 and second clamp 150 may beactuated independently of each other and independently of the bondingapparatus 26 as described and illustrated hereinbefore. Also shown is asoft metal coating 14′ located on the lead finger 14 which is penetratedby either the independent clamp 24 or the second clamp 150. The softmetal coating 14′ applied to the lead finger 14 may be of any suitabletype, such as gold, silver, aluminum, etc., which will allow for theeasy penetration of the coating 14′ by a portion of either theindependent clamp 24 or the second clamp 150.

Referring to drawing FIG. 6A, the independent clamp 24 is shown having alead finger penetrating portion 24′ on the end thereof and clamp 150 isshown having a lead finger penetrating portion 50′ on the end thereofpenetrating the soft metal coating 14′ on the lead finger 14, bothportions 24′ and 50′ penetrating either the lead finger 14 or the softmetal coating 14′ on the lead finger 14 being wire bonded by bondingapparatus 26. As previously described, the lead finger penetratingportions 24′ and 50′ may penetrate the lead finger 14 or any soft metalcoating thereon to any desired depth depending upon the thicknessthereof. However, care should be taken to prevent the lead fingerpenetrating portions 24′ and 50′ from either damaging the lead finger14, affecting its electrical characteristics, or severing the leadfinger 14.

Referring to drawing FIG. 6B, the independent clamp 24 is illustratedhaving a knife edge type penetrating portion 24′ thereon which extendstransversely across the axis of a lead finger 14 (not shown). It shouldbe understood that any suitable shape penetrating portion 24′ may beused on independent clamp 24.

Referring to drawing FIG. 6C, the clamp 150 is illustrated having aknife edge type penetrating portion 50′ thereon which extendstransversely across the axis of a lead finger 14 (not shown). It shouldbe understood that any suitable shape penetrating portion 50′ may beused on clamp 150.

Referring to drawing FIG. 7, a portion of a lead finger 14 isillustrated in relation to a bonding apparatus 26 and independentindividual clamp 100 having a penetrating point 100′ thereon. The clamp100 is generally circular in shape having a frustoconical penetratingpoint 100′ thereon for penetrating a lead finger 14.

Referring to drawing FIG. 7A, the clamp 100 having penetrating point100′ thereon and the bonding apparatus 26 are shown in cross-section inrelation to the penetrating and clamping of a lead finger 14 during wirebonding thereof. The penetrating point 100′ penetrates the lead finger14 to immobilize the lead finger 14 during the wire bonding operation.As previously stated, care should be taken to prevent the leadpenetrating point 100′ from either damaging the lead finger 14,affecting its electrical characteristics, or severing the lead finger14.

Referring to drawing FIG. 8, a bonding apparatus 26 is illustrated inrelation to a lead finger 14 with the independent individual clamp 100having a penetrating point 100′ thereon. As illustrated, the clamp 100is acting on the opposite side of the lead finger 14 from the bondingapparatus 26. It should be understood that any of the penetrating clampshereinbefore described may act on the opposite side of the bondingapparatus 26 during the wire bonding operations regarding a lead finger14. It is not necessary that the penetrating clamp be positioned on thesame side of the lead finger 14 as the bonding apparatus 26. As statedpreviously, care should be taken to prevent the lead penetrating point100′, or the penetrating portion of any penetrating clamp hereinbeforedescribed, from either damaging the lead finger 14, affecting itselectrical characteristics, or severing the lead finger 14.

Method of Bonding

Referring to drawing FIGS. 1 through 3, in the method of the presentinvention, a chip or die 10 is positioned within the bonding area of thebonding apparatus 26. If desired for use in addition to a penetratingindividual independent clamp 24, a conventional or penetrating clamp 22serves to help straighten the lead frame and position the lead fingers14 during subsequent bonding operations. Next, the chip or die 10 andthe lead finger 14 are heated to the desired temperature before bondingoperations by the heat block 20. At this time, the penetratingindividual independent clamp 24 is engaged, moved to the appropriatelead finger 14 which is to have a wire bonded thereto, and actuated toclamp and immobilize the end 15 of the lead finger 14 against the heatblock 20 or the adhesive strip 30. The wire bonding apparatus 26 is thenactuated to form a wire bond on end 17 of wire 16 to an appropriate bondpad on chip or die 10. After the formation of the bond of end 17 of wire16 to the bond pad of die 10, the bonding apparatus is moved to theappropriate end 15 of lead finger 14 for the formation of a suitablewire bond thereto by other end 18 of wire 16. After the formation of thebond of the other end 18 of wire 16 to the end 15 of lead finger 14, thepenetrating individual independent clamp 24 and the bonding apparatusare actuated to remove the independent clamp 24 and the bondingapparatus 26 from the end 15 of the lead finger 14. Alternately, thebonding apparatus 26 is actuated to remove the apparatus from the bondlocation at the end 15 of the lead finger 14 prior to or after theremoval of the penetrating individual independent clamp 24 from a leadfinger 14. During the removal of the bonding apparatus 26 from the end15 of the lead finger 14 the conventional or penetrating clamp 22, if incontact with the end 15 of a lead finger 14, supplies the necessaryforce to retain the lead finger 14 in position relative to other leadfingers located around chip or die 10, both bonded and unbonded. Aspreviously stated, it is not necessary for the penetrating individualindependent clamp 24 to remain in contact with the end 15 of lead finger14 during the removal of the bonding apparatus 26 therefrom. After thewire 16 has been bonded to the desired bond pad of die 10 and end 15 oflead finger 14, the process is repeated until all desired wire bondsbetween lead fingers 14 and the bond pads of chip or die 10 arecompleted.

If desired to have additional clamping of the lead finger 14, either afixed conventional of penetrating clamp 22 and/or a second penetratingindividual independent clamp 24 may be used with the bonding apparatus26. The second penetrating individual independent clamp 24 may beactuated and moved from the lead finger 14 with, before or after theremoval of the bonding apparatus 26 from the lead finger 14.

It will be understood that the present invention may have changes,additions, deletions, modifications, and sequence of operation whichfall within the scope of the invention. For instance fixed clamp may beeliminated and a second independent clamp used in its place.

1. A wire bonding method for a lead finger of a lead frame used in awire bonding apparatus comprising: supporting a portion of a lead fingerof a lead frame in the wire bonding apparatus; contacting a portion ofthe lead finger with a penetrating portion of a penetrating clamp havingat least more than two axes of movement for deforming the portion of thelead finger for retaining the lead finger; providing a bonding apparatusto bond a portion of a wire to the lead finger; actuating the bondingapparatus to bond the portion of the wire to the lead finger; andremoving at least a portion of the penetrating portion of thepenetrating clamp from contact with the portion of the lead fingerbefore removal of the bonding apparatus from the lead finger.
 2. Themethod of claim 1, wherein the penetrating clamp is resiliently mounted.3. The method of claim 1, wherein the penetrating clamp is movable in anx-axis direction, a y-axis direction, and a z-axis direction.
 4. Themethod of claim 1, wherein the penetrating clamp is located on oneportion of the lead finger and the bonding apparatus is located onanother portion of the lead finger.
 5. A method for connecting asemiconductor device having at least one bond pad to a lead frame havingat least one lead finger using a wire bonding apparatus comprising:supporting a portion of the at least one lead finger in the wire bondingapparatus; contacting a portion of the at least one lead finger with aportion of a first clamp for temporarily retaining the at least one leadfinger in position for connecting a conductor thereto; contactinganother portion of the at least one lead finger with a portion of apenetrating clamp for retaining the at least one lead finger in positionfor connecting the conductor thereto, the portion of the penetratingclamp deforming a portion of the at least one lead finger of the leadframe; providing a bonding apparatus to connect the conductor to the atleast one lead finger; actuating the bonding apparatus to connect theconductor to the at least one lead finger; and removing at least aportion of the penetrating clamp from engagement with the portion of theat least one lead finger before removal of the bonding apparatus fromthe at least one lead finger.
 6. The method of claim 5, wherein thepenetrating clamp is resiliently mounted.
 7. The method of claim 5,wherein the penetrating clamp is movable in an x-axis direction, ay-axis direction, and a z-axis direction.
 8. The method of claim 5,wherein the penetrating clamp is located on a portion of the at leastone lead finger and the bonding apparatus is located on another portionof the at least one lead finger.
 9. An apparatus for improved stabilityfor the lead fingers of a lead frame during a wire bonding operation ofconnecting a piece of wire to a bond pad of a semiconductor die and to alead finger of said lead frame comprising: a clamp for engaging aportion of each lead finger of a lead frame during a wire bondingoperation of each lead finger of the lead frame for connecting a bondpad of a semiconductor die to the portion of each lead finger using saidpiece of wire, the clamp having a discrete lead finger penetratingfeature extending therefrom for penetrating the portion of each leadfinger for improved stability of the portion of each lead finger. 10.The apparatus of claim 1, wherein the clamp comprises: an independentclamp having an ability to move independently in x-axis, y-axis andz-axis directions.
 11. The apparatus of claim 1, wherein the clamp ismoveable independently in any direction of movement of the apparatus.12. The apparatus of claim 1, wherein the clamp comprises: a fixed clampfor engaging the portion of each lead finger of the lead frame.
 13. Theapparatus of claim 1, wherein the apparatus exerts a force ofsubstantially 50 to 100 grams for contacting the portion of each leadfinger.
 14. The apparatus of claim 1, further comprising: heatingapparatus located beneath the semiconductor die.
 15. The apparatus ofclaim 14, further comprising: heating apparatus located beneath eachlead finger.
 16. The apparatus of claim 14, wherein the heatingapparatus operates at substantially at least 200° C. to heat thesemiconductor die.
 17. The apparatus of claim 14, wherein thesemiconductor die is heated before being connected to each lead finger.18. The apparatus of claim 9, wherein the clamp is resiliently mountedwith respect to each lead finger of the lead frame.
 19. The apparatus ofclaim 18, wherein the clamp is resiliently mounted through use of aspring engaging a portion of the clamp.
 20. The apparatus of claim 9,wherein the clamp has an end portion thereof including an edge.
 21. Theapparatus of claim 9, wherein the clamp includes an end portion thereofhaving a substantially semicircular shape.
 22. The apparatus of claim 9,wherein the clamp includes an end portion thereof having a substantiallyarcuate shape.
 23. The apparatus of claim 9, wherein the clamp includesa substantially articulated end portion thereof for movement forcontacting the portion of each lead finger.
 24. The apparatus of claim9, wherein the clamp includes a portion for penetrating a portion of athickness of a soft metal coating located on each lead finger.
 25. Theapparatus of claim 9, wherein the at least one discrete lead fingerpenetrating feature includes a point on an end thereof.
 26. Theapparatus of claim 9, further including: a fixed clamp for engaginganother portion of each lead finger.
 27. The apparatus of claim 9,wherein the at least one discrete lead finger penetrating featureincludes a sharp edge thereon.
 28. The apparatus of claim 9, wherein theat least one discrete lead finger penetrating feature includes a roundedportion on a bottom thereof.
 29. The apparatus of claim 9, wherein theat least one discrete lead finger penetrating feature includes aplurality of rounded portions on a bottom thereof.
 30. An apparatus toincrease stability for lead fingers of a lead frame during a wirebonding operation for attaching a portion of a piece of wire to a bondpad of a semiconductor die comprising: a clamp for engaging a portion ofeach lead finger of a lead frame during a wire bonding operation of eachlead finger of the lead frame for connecting a bond pad of asemiconductor die to the portion of each lead finger using a piece ofwire, the clamp for penetrating the portion of each lead finger forstabilizing the portion of each lead finger during the wire bondingoperation.